The Existence of Pure‐Phase Transition Metal Hydroxy Apatites

C. Yoder, Nathan Fedors, Natalie J. Flora, H. Brown, K. Hamilton, C. D. Schaeffer
{"title":"The Existence of Pure‐Phase Transition Metal Hydroxy Apatites","authors":"C. Yoder, Nathan Fedors, Natalie J. Flora, H. Brown, K. Hamilton, C. D. Schaeffer","doi":"10.1081/SIM-200030243","DOIUrl":null,"url":null,"abstract":"Abstract The existence of pure‐phase transition metal hydroxy apatites of zinc, copper, manganese, and cobalt could not be verified by repeated attempts to duplicate the few literature procedures reported for their preparation in aqueous solution. Variations of temperature, time of reactions, pH, and use of decomplexation also did not produce apatitic compounds. In the case of zinc, the product resulting from the addition of zinc nitrate to ammonium dihydrogen phosphate in solutions brought to pH >9 with ammonia appears to be a zinc ammonia complex with phosphate as the counter ion. Extensive drying removed ammonia to produce the phosphate. At pH <8.5 several hydrates of zinc phosphate were formed. With copper, the use of literature procedures and variations thereon resulted in libethenite, Cu2(PO4)OH. The literature procedure for the cobalt(II) apatite using ethylenediamine produced no precipitate; at pH 5, Co3(PO4)2 · H2O was formed in the presence of ethylenediamine. The Mahapatra procedure for the manganese apatite produced a mixture of Mn3(PO4)2 · 3H2O and hureaulite, Mn5(PO4)2[PO3(OH)]2, whereas the Rao method resulted in (NH4)MnPO4 · H2O. On extensive heating all of the products decomposed to the anhydrous phosphate. The instability of the apatites in aqueous solution is attributed to their solubility, supported by an approximate calculation of ΔG dissolution for the zinc apatite. The underlying thermodynamic reason for the solubility appears to be the large negative heat of hydration of the relatively small, polarizable transition metal cations.","PeriodicalId":22160,"journal":{"name":"Synthesis and Reactivity in Inorganic and Metal-organic Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Synthesis and Reactivity in Inorganic and Metal-organic Chemistry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1081/SIM-200030243","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 4

Abstract

Abstract The existence of pure‐phase transition metal hydroxy apatites of zinc, copper, manganese, and cobalt could not be verified by repeated attempts to duplicate the few literature procedures reported for their preparation in aqueous solution. Variations of temperature, time of reactions, pH, and use of decomplexation also did not produce apatitic compounds. In the case of zinc, the product resulting from the addition of zinc nitrate to ammonium dihydrogen phosphate in solutions brought to pH >9 with ammonia appears to be a zinc ammonia complex with phosphate as the counter ion. Extensive drying removed ammonia to produce the phosphate. At pH <8.5 several hydrates of zinc phosphate were formed. With copper, the use of literature procedures and variations thereon resulted in libethenite, Cu2(PO4)OH. The literature procedure for the cobalt(II) apatite using ethylenediamine produced no precipitate; at pH 5, Co3(PO4)2 · H2O was formed in the presence of ethylenediamine. The Mahapatra procedure for the manganese apatite produced a mixture of Mn3(PO4)2 · 3H2O and hureaulite, Mn5(PO4)2[PO3(OH)]2, whereas the Rao method resulted in (NH4)MnPO4 · H2O. On extensive heating all of the products decomposed to the anhydrous phosphate. The instability of the apatites in aqueous solution is attributed to their solubility, supported by an approximate calculation of ΔG dissolution for the zinc apatite. The underlying thermodynamic reason for the solubility appears to be the large negative heat of hydration of the relatively small, polarizable transition metal cations.
纯相变金属羟基磷灰石的存在
锌、铜、锰和钴的纯相变金属羟基磷灰石的存在,不能通过重复几种文献报道的水溶液制备方法来验证。温度、反应时间、pH值和解解作用的变化也不会产生磷灰石化合物。以锌为例,在pH >9的溶液中,用氨将硝酸锌加入磷酸二氢铵,得到的产物是以磷酸盐为反离子的氨锌络合物。广泛的干燥除去了氨以产生磷酸盐。在pH <8.5时,形成了几种磷酸锌水合物。对于铜,使用文献程序及其变化可得到褐铁矿Cu2(PO4)OH。文献中采用乙二胺法制备钴(II)磷灰石无沉淀;在pH为5的条件下,乙二胺存在下生成Co3(PO4)2·H2O。锰磷灰石的Mahapatra法得到Mn3(PO4)2·3H2O和水辉石Mn5(PO4)2[PO3(OH)]2的混合物,而Rao法得到(NH4)MnPO4·H2O。经广泛加热后,产物全部分解为无水磷酸盐。磷灰石在水溶液中的不稳定性归因于其溶解度,由锌磷灰石的近似计算ΔG溶解度支持。溶解度的潜在热力学原因似乎是相对较小的、可极化的过渡金属阳离子的水化负热很大。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信